I spent many of my college days organizing sit-ins and marches, and being jailed for my efforts; and my first meeting with Martin Luther King Jr. in October 1960 was a life-altering experience. So I was highly disappointed when preparations for my second year as a public school teacher in Charleston, S.C., prevented my participation in the historic March on Washington. Although my body was in South Carolina, like millions of Americans, my heart and soul were in Washington, D.C.

But unlike millions of Americans, Dr. King's soaring oration of the "Dream" was not what captured my attention at that march. Instead, it was his theme of the "fierce urgency of now" that resonated strongly with me. Dr. King and many of us during that era had grown weary of being told to "wait," that the time was not right. As he stood before the Lincoln Memorial, Dr. King intoned, "This is no time to engage in the luxury of cooling off or to take the tranquilizing drug of gradualism. Now is the time to make real the promises of democracy."

Even with that call for urgency, it would be several years before the segregated schools in which I began my career were integrated. Thanks to the persistence of Dr. King, Septima Clark, John Lewis and many others, slowly but surely significant progress was made. And when Barack Obama was elected our nation's 44th president, many believed the United States had finally turned the corner on racial equality. Since that high point, however, the political pendulum has swung dramatically to the right and we have begun to witness the unraveling of much that took nearly a century to achieve.

We are experiencing manufactured controversies and coordinated misrepresentations designed to undermine the president and devalue the presidency. Legislative efforts to deny access to affordable health care, educational opportunities and an unfettered ballot are sweeping the country. Judicial decisions equating corporations with people, money with speech, and effective representation with voter participation are becoming the norm. We seem to be standing on what Dr. King called the "quicksands of racial injustice."

As I watch these efforts unfold and grab hold, I am concerned at the lack of urgency among the affected groups. On Capitol Hill, the Congressional Black Caucus, Congressional Hispanic Caucus and the Congressional Asian and Pacific Americans Caucus are sounding alarms, but we don't feel the groundswell from the grass roots.

As we celebrate the March on Washington's 50th anniversary, let's not forget what that petition was all about. We must remember that following the Emancipation Proclamation, black Americans were integrated into the mainstream of American government, business and society. But in its 1875 Cruikshank decision, the U.S. Supreme Court gave rise to decades of creative devices of "interposition and nullification" in state after state; and in its 1896 Plessy v. Ferguson decision established "separate but equal" as the law of the land and it remained so for the next 60 years.

As a teacher, I often cautioned my students that anything that's happened before can happen again. Today, I often remind audiences of George Santayana's admonition that, if we fail to learn the lessons of our history, we are bound to repeat them.

I am hopeful that current generations have learned the lessons of that history, a benefit our forebears did not have. Hopefully, we will not succumb to the "tranquilizing drug of gradualism," as Dr. King warned, and remember his summon that "now is the time to make real the promise of democracy" and ensure that the promise is applied equitably and for eternity.

Congressman James E. "Jim" Clyburn has been the U.S. representative for South Carolina's 6th Congressional District since 1993 and the assistant Democratic leader since 2011. He was House majority whip from 2007 to 2011.